Automatic draft-regulator.



J. W. MICKLESON.

AUTOMATIC DRAFT REGULATOR.

APPLICATION FILED APILZO, 1012.

1 ,()73,81 0, Patented Sept. 23, 1913.

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an neuter J. W. MICKLESON.

AUTOMATIC DRAFT REGULATOR.

APPLICATION FILED APB..20,1912.

1 ,073,8 1 O. Patented Sept. 23, 1913.

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'UNTE @TATES ATENT OFFICE.

JAMES W. MICKLESON, OF DAYTON, IDAHO, ASSIGNOR OF ONE-HALF TO THOMAS MORRISON, OF DAYTON, IDAHO.

AUTOMATIC DRAFT-REGULATOR.

Specification of Letters Patent.

Patented Sept. 23,1913.

Application filed April 20, 1912. Serial No. 691,988.

To all whom it may concern Be it known that I, James W. Mionnn- SON, a citizen of the United States, residing at Dayton, in the county of Oneida and State of Idaho, have invented certain new and useful Improvements in Automatic Draft-Regulators, of which the following is a specification.

This invention relates to automatic draft controls for boilers and has for an object to provide a novel coil spring adapted to respond to changes in the steam pressure, novel means being operatively connected to this spring and to the dampers of the boiler for opening the dampers at a fall in pressure below a predetermined point, and for closing the dampers at a rise in pressure above a predetermined point.

A still further object of the invention is to provide means for relieving the coil spring of the weight of the damper, and to further provide means for adapting the device to various sizes of boilers.

WVith the above objects in view the invention consists of certain novel details of construction and combination of parts hereinafter fully described and claimed, it being understood that various modifications may be made in the minor details of construc tion within the scope of the appended claims.

In the accompanying drawings forming part of this specification :Figure 1 is a side elevation of a boiler equipped with my improved draft regulator. Fig. 2 is a longitudinal sectional view through the regulator with parts in elevation. Fig. 3 is a cross sectional view taken on the line 33 Fig. 2. Fig. t is a longitudinal sectional view taken on the line ll Fig. 2. Fig. 5 is a detail perspective view of the bracket. Fig. 6 is a fragmentary detail view of a modified form of tubular sprin Referring now to the drawings in which like characters of reference designate simi lar parts, 10 designates a boiler having a damper 11 at the front of the fire box and a damper 12 at the rear of the fire box. Bell crank levers 13 and 14 are connected through the instrumentality of rods 15 and 16 to the damper handles as shown, both bell crank levers being connected through the instrumentality of a toggle lever 17 to the lower end of a stand rod 18 which is adapted to be raised and lowered by a hereinafter described mechanism during fluctuations in steam pressure, and during a drop in the pressure below a predetermined point, both dampers will be simultaneously opened as shown in dotted lines in Fig. 1, while during a rise in pressure above the predetermined point, both dampers will be simultaneously closed.

The above construction illustrates one method of regulating dampers by my improved regulator about to be described, but it is to be understood that any mechanism suitable to simultaneously operate both dampers, or to operate but a single damper, may be used in connection with my draft regulator which forms the snbject-n'iatter of this invention.

The draft regulator consists essentially of spaced coil springs 19 preferably formed of tubular material having sullicient resiliency to permit of the springs expanding upon an incr vase in steam pressure within the springs and contracting upon a drop in steam pressure. The inner terminal of each spring is flattened as shown at 20, and these flattened terminals are connected by a pin 21. The outer terminal 22 of each spring is substantially straight and the straight terminals of both springs are connected to a branched steam pipe 23 which is in turn connected to a steam pipe 2 which leads into the steam dome 25 of the boiler, a valve 26 being interposed between the branched steam pipe 23 and steam pipe i l as shown.

Experience has proved that to adapt the spring to various conditions of service, an elongated strip of resilient material such as steel or the like, may be brazed or otherwise fixed to the convolution of the spring as shown at 27 in the fragmentary Fig. (3 to reinforce the spring and supply the neces sary resiliency to attain the end sought.

For transi'nitting movement of the springs 19 to the stand rod 18, I arrange a slide bar within a casing 29 which houses the springs, the slide bar being provided in opposite sides with guide grooves 30 which receive pins 31 the latter slidably attaching the slide bar to the casing. An eye screw 32 is threaded into the slide bar, and a connecting pin 33 passed through the eye of the screw and through the upper end of the stand rod. A rock link 34, having the movement of a walking beam, is hingedly connected at one end as shown at 35 to the slide bar 28, and is provided at the opposite end with an orifice which loosely receives the connecting pin 21 of the springs 19. Upon contraction of the spring the rock link will lower the stand rod, and open the dampers, and upon expansion of the springs the rock link will raise the slide bar and close the dampers.

For pivotally supporting the rock link, a bracket 35 is secured to one side of the casing, the bracket having a substantially straight portion 36 which extends in parallelism with the rock link when the latter is in normal or horizontal position, and divergent legs 37 which are bolted or otherwise secured as shown at 38 to the casing. Reg istering slots 39 and i0 are formed in the rock link and in the straight portion of the bracket respectively, and a set screw 41 is adjustably secured in these registering slots and loosely secures the rock link to the bracket. The set screw forms the fulcrum of the rock link, and it is clear that this fulcrum may be adjusted to any position longitudinally of the slot in the bracket to regulate the throw of the working end d2 of the rock link so as to adapt the device to various sizes of boilers.

For balancing the rock link in order to remove the weight of the dampers and operating mechanism from the springs, a l1elical spring 453 is connected to the rock link intermediate the fulcrum thereof and the springs as shown at 44, and is adjustably connected to the top of the casing through the instrumentality of a threaded pin so, a cylindrical housing 46 being secured to the casing and housing the pin and spring as shown. The spring exerts a pressure upon the rock link suflicient to normally hold the same balanced, or in other words in horizontal position.

By now referring to Fig. 2 it will be seen that pivotally mounted within the casing is a cam lever 47 which bears upon the upper extremity of the slide rod. By shifting this cam lever forwardly, the dampers 11 and 12 are closed under high pressure of steam in order to permit of the fires being banked at night.

lVhat is claimed, is

1. A damper regulator including spaced helical tubular springs forming steam ducts and each adapted to be connected to the steam space of a boiler, a slide bar adapted to be connected to a damper, a rock link connected to said slide bar and having the move ment of a walking beam, a single pivot passed through said rock link and the inner ends of the convolutions of said springs, and performing the dual function of connecting together said springs and pivotally connecting said rock link to said springs, and damper controlling means carried by the free end of said link.

2. A damper regulator including a curvilinear tubular spring forming a steam duct, a slide bar adapted to be operatively connected to a damper, a rock link having the movement of a walking beam and operatively connected to the free end of said spring and to said slide bar, a stationary bracket, a fulcrum pin for said rock link adjustably secured to said rock link and con nected to said bracket, and a tension device disposed between said bracket and said spring and operatively connected to said rock link between said fulcrum pin and said spring and serving to counterbalance the weight of said slide bar and connections thereof with said damper on said rock link.

In testimony whereof I aflix my signature, in the presence of two witnesses.

JAMES l/V. MIGKLESON.

\Vitnesses J. N. LARSEN, 'MINNIE BAIN.

Goggles of this patent may be obtained for five cents each, by addressing the Commissioner of Patents.

Washington, D. C. 

